Genome mapping in Capsicum and the evolution of genome structure in the Solanaceae

We have created a genetic map of Capsicum (pepper) from an interspecific F- 2 population consisting of 11 large (76.2-192.3 cM) and 2 small (19.1 and 1 2.5 cM) linkage groups that cover a total of 1245.7 cM. Many of the markers are tomato probes that were chosen to cover the tomato genome, allowing co mparison of this pepper map to the genetic map of tomato. Hybridization of all tomato-derived probes included in this study to positions throughout th e pepper map suggests that no major losses have occurred during the diverge nce of these genomes. Comparison of the pepper and tomato genetic maps show ed that 18 homeologous linkage blocks cover 98.1% of the tomato genome and 95.0% of the pepper genome. Through these maps and the potato map, we deter mined the number and types of rearrangements that differentiate these. spec ies and reconstructed a hypothetical progenitor genome. We conclude there h ave been 30 breaks as part of 5 translocations, 10 paracentric inversions, 2 pericentric inversions, and 4 disassociations or associations of genomic regions that differentiate tomato, potato, and pepper, as well as an additi onal reciprocal translocation, nonreciprocal translocation, and a duplicati on or deletion that differentiate the two pepper mapping parents.